Hot water heating system



Feb. 15, 1949. L. R. ROBERTSON 2,461,774

HOT WATER HEATING SYSTEM Filed May 26, 1947 III-Io 6 28 w @Llllll 4 i mm 5 i, U 29 r F 2! 7 I I -l5 n n l ii ii I IGFLFI 1'! as u !I%\ -5: 1 J l l kl lai l =20 20 F/G. I. 22 7 l 2 JNVENTOR. LEROY R. ROBERTSON FIG. 2.

special valve arrangements.

Patented Feb. 15, 1949 UNITED STATES PATENT OFFICE HOT WATER HEATING SYSTEM Leroy R. Robertson, Richmond, Va.

Application May 26, 1947, Serial No. 750,521

4 Claims. 1

This invention relates to hot water heating circulating systems for domestic purposes. More particularly the invention involves the use of electrical energy for heating the system through a suitable heat-exchanging system.

The usual method of heating hot-waterheating systems is through the use of a boiler fed by coal, oil or other combustible materials. This requires a heavy initial expenditure of money and follows with high maintenance costs. In addition the auxiliaries needed for heating, absorb considerable heat within themselves that is of little practical value to the user and adds to his costs. In other instances a heat exchanger is used connected to a central heating system and requires the use of steam transported from a distant point. This system is relatively expensive to the user because of the transmission losses and the capital required in the original investment to install it. There are many details to this system that further add to its expense and the cost of the maintenance, such as traps, special meters pumps, and much piping with The result is, that the user finds the cost in either system very much the same to him, and only a local advantage will enable him to select which he shall use.

In this invention. the arrangement is economical in the initial investment. low in maintenance costs and its cost of operation less than coal or oil. It is considerably more flexible than the coal or fuel oil systems; is safer to use and operate, and requires the very simplest skill to control its use.

It is the cleanest system available at the present time, and the amount of space required for the installation of its main operating parts is out down to a minimum and it is placeable in any convenient part of a building.

It is therefore an obiect of the present invention to provide a new and improved domestic heating system that will avo d one or more of the disadvantages and limitations of the prior art.

Another object of the invention is to provide a new and improved domestic heating system that will employ electricity as the heat ng medium and do so in a most efficient and effective manner.

A further object of the herein described invention is to provide a new and im roved domestic hot water heating system that will employ a heating unit filled with mineral oil or a like substance to convey the heat from electrical immersion heaters to tubing immersed in said mineral oil through which the radiator heating water circulates, and having effective automatic control for said electrical heating means and radiator heating water and its circulation through said system.

Other objects will become apparent as the invention is more fully set forth.

For a better understanding of the invention, and the objects thereof, reference is made to the appended drawings and the description following. These together, describe and illustrate a particular form of the invention by way of example and explain the general principles and operation of the system employed, while the claims included, indicate the scope of the invention.

In the drawings:

Figure 1 is a diagrammatic View of the heating system embodying this invention;

Figure 2 is a side view of Figure 1, with parts broken away. to show its inner construction, and

Figure 3 is a diagrammatic wiring diagram.

Similar reference numerals refer to similar parts throughout the drawings.

The drawings show a hot water heating system 5 of the summer-winter type comprising a heat exchanger '1 located at a suitable location and having its hot water coils 8 connected at one end to a riser S which feeds radiators H3 and returns through piping H to a circulator pump t2 thence back to the opposite end of the water coils 8. The water coils are surrounded by an oil or other suitable heat transmitting or transfer fluid 13 which flows out the bottom of the heat exchan er 1 through piping M to a series of heating shells l5 into which are inserted electrical heaters f5, which are preferably arranged vertically therein and in separate shells as shown, These shells lead to the upper main I? which carries the heated fluid back to the heat exchanger i to complete the circuit, and start a new rotation. An expansion bleeder pipe !8 w th expansion tank iii attached thereto. takes care of the expansion involved in the heating fluid I3 in the heating system. The heaters H; are held in place in the shells M5 by special fittings 2D. A thermostat 2! makes demand for heat on a magnetic switch 22 which in closing turns on the heaters H3 n the shells 35 thereby heating the fluid 1'3 until the water in the coils 8 reaches a predetermined temperature to operate the aquastat this causes the circulator E2 to start operating and draws the cooler water from the return line H and causes the heated water to leave the heat exchanger and flow up to the radiators I 0 thence back through the return lines I in case of electrical trouble in the heaters.

ll back to the heat exchanger. Another aquastat 24 used as a high limit control to override thethermostat 2i demand until the oil fluid i3 has cooled suificiently to again heat the oil I3 until the thermostat is satisfied. A pressuretrol 25 is positioned in the piping I4 to override the thermostat 2| in case of the failure of the aquastat limit control 2d. The thermostat 2i, aquastat 24 andpressuretrol 25 are wired in series. The pressuretrol is used only in case the aquastat 2 or thermostat 26 should fail, thus protecting the system from any undue pressure.

There are several fluids suitable for the purposes of transmitting heat that are commercially known and need not be detailed further herein. The characteristics of one of the fluids is that it has a low specific heat, its flash point is high, and remains fluid through a large range of temperatures, and it is relatively odorless. Of course water could be used also, but its high specific heat requirement reduces the efliciency, of the system, and .does not make itso desirable, even though it is relatively cheap to provide. Water is used in the main heating system 8 as a matter of convention and general suitability. If there is danger of freezing in a particular instance, another suitable liquid could be substituted, but ordinarily the system would be drained of its water where there is danger of freezing when the system is not in operation.

The general operation of the system is as follows:

The heaters i5 are controlled by switch 25 by applying the electricity or current from the circuit 2? through the magnetic switch 22. As the heaters heat up. they heat the fluid I3, which immediately circulates by gravity or the use of the circulator into the heat-exchanger 7: and returns through angularly disposed piping back to the heaters. The heaters are controlled so they cannot excessively heat the fluid 53 passing through the heat exchanger I and the water in the system 8 is heated by the coils 3 and is circulated through the radiators and piping in the usual manner.

Other instruments may be provided in the sys tems to suit the needs or desires of the user, and may include such items, as thermometer 28, vents 29.

The use of an oil or similar non-electrical conducting fluid is preferred to that of mercury and other low specific heat conducting mediums, as the heating fluid, because of its relatively greater safety from the eifects of electricity, especially The system is so simple that little space is required for its accommodation and it can be made up into a very neat and attractive unit, which would make its placement unobjectionable anywhere. When once switched on, it works automatically, and even though the electricity should be shut oiT temporarily no special great danger would arise. In the case of a conventional furnace burning oil fuel or coal such situations might induce fires and explosions and endanger the general safety of the community far beyond the vicinity of the apparatus.

The use of a housing to include the piping, and heat exchanger, and insulated to reduce heat losses. from the unit is preferred and in many instances. would make a complete unit Very attractive in form.

While but one general form of the invention is shown in the drawings and described in the specifications, it is not desired to. limit this applicaa tionior. patent to thisparticular form orin any other way otherwise than limited by the scope thereof, as it is appreciated that other forms of construction could be made that would use the same principles and come within the scope of the appended claims.

Having thus described the invention, what is claimed is:

1. A heating system comprising in combination a heat exchanger having tubing aligned therein, a heating fluid surrounding said tubes for transferring its heat to the interior of said tubes, electrical heating elements for heating said fluid, piping connected to said heat exchanger for supporting electrical heating elements and circulating the heating fluid from the exchanger to the heating elements and back to the exchanger, riser piping connected to one end of the exchanger tubing and running to heating radiatorsthen returning to the opposite end of the exchanger tubing for carrying the heated radiator water to the radiators, an expansion tank and bleeder attached to said heat exchanger, a circulator pump positioned in said return line, and

the circulator to force the hot radiator water from the heat exchanger through the radiators and return, another aquastat mounted in the return line used as a high limit control to override the thermostat demand until the fluid has cooled sufficiently until the thermostat is satisfied a pressuretrol also positioned in the riser piping to override the thermostat in case of the failure of the aquastat limit control, the thermostat, aquastat in the return piping and the pressuretrol in the upper main pipe being wired in series, the pressuretrol being used only in case the aquastat in the return line or thermostat should fail to operate properly, thereby protecting the system from any undue pressure.

2. A heating system comprising in combination a heat exchanger having tubing aligned therein, a heating fluid surrounding said tubes for transferring its heat to the interior of said tubes, electrical heating elements for heating said fluid, piping connected to said heat exchanger for supporting electrical heating elements and circulating the heating fluid from the exchanger to the heating elements and back to the exchanger, riser piping connected to one end of the exchanger tubing and running to heating radiators then returning the opposite end of the exchanger tubing for carrying the heated radiator water to the radiators, an expansion tank and bleeder attached to said heat exchanger, a room thermostat for making demands on a magneticswitch for closing the electrical circuit and energizing the heaters and heating the heating fluid to a predetermined temperature, an aquastat mounted on the riser line for operating the circulator to force the hot radiator Water from the heat exchanger through the radiators and return, another aquastat mounted in the return line used as a high limit control to override the thermostat demand until the fluid has cooled sufficiently until the thermostat is satisfieda pressuretrol also positioned in the riser piping to override the thermostat in case of the failure of the aquastat limit control, the thermostat, aquastat in the -re-- turn piping and the pressuretrol in the upper main pipe being wired in series, the pressuretrol-being used only in case,theaquastatinthd return line ,5 or thermostat should fail to operate properly, thereby protecting the system from any undue pressure.

3. A heating system comprising in combination a heat exchanger having tubing aligned therein, a heating fluid used as a heat transfer medium consisting of a high grade-non-destructibleodorless vegetable oil (similar to mineral oil) with a Fahr. value of approximately 600 deg. and 400 flash point surrounding said tubes for transferring its heat to the interior of said tubes, electrical heating elements for heating said fluid, piping connected to said heat exchanger for supporting electrical heating elements and circulating the heating fluid from the exchanger to the heating elements and back to the exchanger, riser piping connected to one end of the exchanger tubing and running to heating radiators then returning to the opposite end of the exchanger tubing for carrying the heated radiator water to the radiators, an expansion tank and bleeder attached to said heat exchanger, a room thermostat for making demands on a magnetic switch for closing the electrical circuit and energizing the heaters and heating the heating fluid to a predetermined temperature, an aquastat mounted on the riser line for operating the circulator to force the hot radiator water from the heat exchanger through the radiators and return, another aquastat mounted in the return line used as a high limit control to override the thermostat demand until the fluid has cooled sufliciently until the termostat is satisfied a pressuretrol also positioned in the riser piping to override the thermostat in case of the failure of the aquastat limit control, the thermostat, aquastat in the return piping and the pressuretrol in the upper main pipe being wired in series, the pressuretrol being used only in case the aquastat in the return line or thermostat should with a Fahr. value of approximately 600 deg. and 400 flash point surrounding said tubes for transferring its heat to the interior of said tubes, electrical heating elements for heating said fluid, piping connected to said heat exchanger for supporting electrical heating elements and circulating the heating fluid from the exchanger to the heating elements and back to the exchanger, riser piping connected to one end of the exchanger tubing and running to heating radiators then returning to the opposite end of the exchanger tubing for carrying the heated radiator water to the radiators, an expansion tank and bleeder attached to said heat exchanger, a room r thermostat for making demands on a magnetic switch for closing the electrical circuit and energizing the heaters and heating the heatingfluid to a predetermined temperature, an aquastat mounted on the riser line for operating the circulator to force the hot radiator water from the heat exchanger through the radiators and return, another aquastat mounted in the return line used as a high limit control to override the thermostat demand until the fluid has cooled sufficiently until the thermostat is satisfied a pressuretrol also positioned in the riser piping to override the thermostat in case of the failure of the aquastat limit control, the thermostat, aquastat in the return piping and the pressuretrol in the upper main pipe being Wired in series, the pressuretrol being used only in case the aquastat in the return line or thermostat should fail to operate properly, thereby protecting the system from any undue pressure, and a circulator pump positioned in said return line.

LEROY R. ROBERTSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

